System and method for water treatment

ABSTRACT

System and method of treating waste water includes: receiving waste water at a first pressure and temperature, the waste water comprising dissolved solids and VOCs; pressurizing, by a pump, the received waste water to a second pressure greater than the first pressure; preheating, by a preheater, the waste water to a second temperature greater than the first temperature producing distilled water; further heating, by a condenser, the pressurized/preheated waste water to a fourth temperature greater than the second temperature; still further heating, by a heater, the pressurized/further heated waste water to a third temperature greater than the fourth temperature; and removing, by a flash evaporator, dissolved solids from the pressurized/heated waste water by evaporation producing steam and brine water, the brine water having a TDS content greater than a TDS content of the received waste water. The brine water may be crystallized to a solid mass.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication Nos. 61/573,900, 61/573,957, 61/573,958, 61/573,956,61/573,955, 61/573,954, 61/573,953 and 61/573,952, all filed on Sep. 14,2011, the disclosures of which are hereby incorporated by reference intheir entireties.

FIELD OF THE INVENTION

The present invention is generally directed toward the treatment ofwater and, more particularly, toward the treatment of water containinglarge amounts of dissolved solids as may result, for example, from useof the water as a fracking fluid used in drilling gas wells. However,the embodiment proposed herein may be used in any situation whereimpurities to be removed from water exist.

BACKGROUND OF THE INVENTION

Ensuring a supply of potable water has been a frequent concern in manylocations. Further concerns arise about the environmental impact of thedisposal of contaminated water.

Conventional water treatment techniques for such purposes as, forexample, municipal water treatment and/or obtaining potable water fromsea water are known and are successful in many instances. However, somecurrent activities show those techniques to have limited costeffectiveness.

For example, mining with water used to fracture rock or shale formationsto recover natural gas (e.g., in the shale regions in the United Statesand western Canada including, but not limited to, Pennsylvania,Maryland, New York, Texas, Oklahoma, West Virginia and Ohio) requires avery large amount of water input and a significant amount of return(flowback) water that contains a great deal of contaminants andimpurities. In order for this flowback water to be used in anenvironmentally responsible manner, it needs to be relatively free ofcontaminants/impurities. Water used, for example, in natural gas welldrilling and production may contain organic materials, volatile andsemi-volatile compounds, oils, metals, salts, etc. that have madeeconomical treatment of the water to make it potable or reusable, oreven readily and safely disposable, more difficult. It is desirable toremove or reduce the amount of such contaminants/impurities in the waterto be re-used, and also to remove or reduce the amount of suchcontaminants/impurities in water that is disposed of.

The present invention is directed toward overcoming one or more of theabove-identified problems.

SUMMARY OF THE INVENTION

The present invention can take numerous forms among which are those inwhich waste water containing a large amount of solids, including, forexample, dissolved salts, is pressurized to allow considerable heat tobe applied before the water evaporates, and is then subjected toseparation and recovery apparatus to recover relatively clean water forreuse and to separate solids that include the afore-mentioned dissolvedsalts. In some instances, the concentrated solids may be disposed of asis, e.g., in a landfill. Where that is not acceptable (e.g., for reasonsof leaching of contaminants), the concentrated solids may be supplied toa thermal, pyrolytic, reactor (referred to herein as a “crystallizer”)for transforming them into a vitrified mass which can be placed anywhereglass is acceptable.

Particular apparatus for systems and processes in accordance with thepresent invention can be adapted from apparatus that may be presentlycurrently available, but which has not been previously applied in thesame manner. As an example, conventional forms of flash evaporationequipment, such as are used for treating sea water, in one or inmultiple stages, may be applied herein as separation and recoveryapparatus. Likewise, conventional forms of gasification/vitrificationreactors, such as are used for municipal solid waste (“MSW”) processingincluding, but not limited to, plasma gasification/vitrificationreactors, may be applied for final separation of the contaminants fromthe water and for initial heating of the waste water.

The present disclosure presents examples of such systems and processesin which, in one or more successive concentration stages, waste waterwith dissolved solids (e.g., salts) is pressurized (e.g., from 14.7 psiato 150 psia) and heated (e.g., to 358° F.) before flash evaporation ofthe waste water to a significantly lower flash pressure and temperature(e.g., 25 psia and 239° F.) of the output brine water with moreconcentrated salts (e.g., higher Total Dissolved Solids—“TDS”).

Steam output from the various concentration stages may be, at least inpart, supplied to a stripper to remove volatile organic compounds(“VOCs”) which are also included in the waste water.

Depending on the nature of the levels of the TDS, the brine water fromthe various concentration stages may be utilized, as is, for other uses,e.g., de-icing fluid, etc., with a significant amount of clean waterrecovered (e.g., as distilled water from heat exchangers of theconcentration stages). The brine water may alternatively be treated in athermal (e.g., plasma) reactor or crystallizer in order to separate thesalts and recover water included in the brine water from theconcentration stages.

Examples also include supplying saturated steam from the crystallizerdirectly to the condensers of the concentration stages, and then fromeach of which it is then applied as a heating fluid or source of apreheater for the waste water. Incoming waste water or brine water toeach concentration stage is initially pressurized and heated (e.g., to230° F.) by, for example, a pump, a preheater, and a condenser by use ofthe steam from the crystallizer and/or from the flash evaporator of thatstage. The waste water is further heated, prior to flash evaporation, byan additional heater that uses another heating fluid or source, e.g.,DowTherm™, to increase the temperature to the flash temperature, e.g.,to 358° F.

A method for treating waste water is disclosed, the method including thesteps of: (a) receiving waste water at a first pressure and a firsttemperature, the waste water comprising dissolved solids, volatileorganic compounds and other components generally and collectively calledimpurities; (b) pressurizing the received waste water to a secondpressure greater than the first pressure; (c) preheating the pressurizedwaste water to a second temperature greater than the first temperature,wherein said preheating step produces distilled water andpressurized/preheated waste water without boiling of the waste wateracross heat transfer surfaces; (d) heating the pressurized/preheatedwaste water to a third temperature greater than the second temperatureto produce pressurized/heated waste water without boiling of the wastewater across heat transfer surfaces; and (e) removing dissolved solidsfrom the pressurized/heated waste water by evaporation caused bydepressurization of the waste water to produce steam and brine water,wherein the brine water has a total dissolved solids content greaterthan a total dissolved solids content of the received waste water.

In one form, step (d) may include the steps of: (d1) further heating thepressurized/preheated waste water to a fourth temperature greater thanthe second temperature and less than the third temperature to producepressurized/further heated waste water without boiling of the wastewater across heat transfer surfaces; and (d2) still further heating thepressurized/further heated waste water to the third temperature toproduce pressurized/heated waste water without boiling of the wastewater across heat transfer surfaces.

The heating performed in step (d2) may be performed using an externalheat source, such as, for example, DowTherm™.

The first pressure may be approximately 11.8-17.6 psia, and the firsttemperature may be approximately 48-72° F.

The second pressure may be approximately 120-180 psia, and the thirdtemperature may be approximately 286-430° F.

The second temperature may be approximately 68-140° F.

The fourth temperature may be approximately 184-276° F.

In another form, the steam produced in step (e), when cooled, producesdistilled water. Additionally, the steam produced in step (e) may beused as a heat source in at least one of steps (c) and (d). Alternately,the steam produced in step (e) may be used as a heat source in at leastone of steps (c) and (d1).

In a further form, steps (a)-(e) comprise a stage, and wherein themethod is performed in multiple stages with the brine water output bystep (e) in one stage used as the received waste water in step (a) of anext stage. The brine water output in step (e) of each stage has a totaldissolved solids content that is higher than that of a previous stage.

In yet a further form, the method further includes the steps of: (f)crystallizing the brine water to produce a solid mass of waste productand steam. The steam produced by step (f) may be used as a heat sourcein at least one of steps (c) and (d) or, alternately, in at least one ofsteps (c) and (d1). A plasma crystallizer using a plasma torch may beused to crystallize the brine water. The solid mass of waste product mayinclude a vitrified glass of the salts in the brine water.

In still a further form, the method further includes the steps of: (b′)prior to step (b), removing the volatile organic compounds from thereceived waste water, wherein the removed volatile organic compounds areused as a heat source by the plasma torch to crystallize the brinewater. The steam produced in step (f) may be used as a heat source instep (b′).

A system for treating waste water is also disclosed, the systemincluding: a pump receiving waste water at a first pressure and a firsttemperature and pressurizing the received waste water to a secondpressure greater than the first pressure, the waste water comprisingdissolved solids, volatile organic compounds and other componentsgenerally and collectively called impurities; a preheater receiving thepressurized waste water from the pump and preheating the pressurizedwaste water to a second temperature greater than the first temperatureto produce distilled water and pressurized/preheated waste water withoutboiling of the waste water across heat transfer surfaces; a condenserreceiving the pressurized/preheated waste water and further heating thepressurized/preheated waste water to a fourth temperature greater thanthe second temperature to produce a pressurized/further heated wastewater without boiling of the waste water across heat transfer surfaces;a heater receiving the pressurized/further heated waste water and stillfurther heating the pressurized/further heated waste water to a thirdtemperature greater than the fourth temperature to producepressurized/heated waste water without boiling of the waste water acrossheat transfer surfaces; and an evaporator removing dissolved solids fromthe pressurized/heated waste water by evaporation caused bydepressurization of the waste water to produce steam and brine water,wherein the brine water has a total dissolved solids content greaterthan a total dissolved solids content of the received waste water. Theevaporator may include a flash evaporator. The heating performed by theheater may be performed using an external heat source, such as, forexample, DowTherm™.

The first pressure may be approximately 11.8-17.6 psia, and the firsttemperature may be approximately 48-72° F.

The second pressure may be approximately 120-180 psia, and the thirdtemperature may be approximately 286-430° F.

The second temperature may be approximately 68-140° F.

The fourth temperature may be approximately 184-276° F.

In one form, the steam produced by the evaporator may include distilledwater. The steam produced by the evaporator is used as a heat source byat least one of the preheater and the condenser.

In another form, the pump, preheater, condenser, heater and evaporatorcomprise a stage, and wherein the system comprises multiple stages withthe brine water output by one stage used as the received waste water ofa next stage. The brine water output by each stage has a total dissolvedsolids content that is higher than that of a previous stage.

In a further form, the system further includes a crystallizercrystallizing the brine water to produce a solid mass of waste productand steam. The steam produced by the crystallizer may be used as a heatsource by at least one of the preheater and condenser. The solid mass ofwaste product may include a vitrified glass of the salts in the brinewater.

In yet a further form, the crystallizer includes a plasma crystallizerand includes a plasma torch for vaporizing the water from the brinewater and producing the solid mass of waste product and steam.

In still a further form, the system further includes a stripperinitially receiving the waste water and removing volatile organiccompounds from the waste water prior to the waste water beingpressurized by the pump, wherein the removed volatile organic compoundsare used as a heat source by the plasma torch to crystallize the brinewater. The steam produced by the crystallizer may be used as a heatsource by the stripper.

Further explanations and examples of various aspects of the presentinvention are presented in the following disclosure.

It is an object of the present invention to provide a system and methodfor the economic and environmental treatment of waste water.

Various other objects, aspects and advantages of the present inventioncan be obtained from a study of the specification, the drawings, and theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Further possible embodiments are shown in the drawings. The presentinvention is explained in the following in greater detail as an example,with reference to exemplary embodiments depicted in drawings. In thedrawings:

FIGS. 1, 2 and 3 are schematic flow diagrams of particular examples ofvarious stages of a water treatment system in accordance with thepresent invention; and

FIG. 4 is a schematic flow diagram of an exemplary thermal reactor foruse in a water treatment system in conjunction with elements such asthose shown in FIGS. 1-3, in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1, 2 and 3 will be individually discussed, but first theirrelation to each other in an example multi-stage system will bedescribed. FIG. 1 shows Stage #1. This first stage, shown generally at5, takes in waste water at an inlet 10, processes it, and produces firststage brine water at an outlet 30 of the first stage. The first stagebrine water from the outlet 30 is then input to the second stage (Stage#2) shown in FIG. 2. The second stage, shown generally at 5′, takes inthe brine water 30, performs additional processing on it, and produces aresulting second stage brine water output at an outlet 50. Similarly,the brine water from outlet 50 of the second stage is supplied as aninput to the third stage (Stage #3) shown in FIG. 3. The third stage,shown generally at 5″, receives the brine water 50, performs furtherprocessing, and produces a resulting third stage output of brine waterat an outlet 70.

It will be seen and appreciated by on skilled in the art how thesuccessive stages of FIGS. 1, 2 and 3 increase the concentration ofsalts in the brine water (e.g., TDS). It will also be appreciated howthe number of stages is a variable that can be chosen according tofactors including, but not limited to, the salts content of the originalwaste water and the desired salt content after concentration. Ingeneral, a system in accordance with these exemplary embodiments mayinclude any one or more stages such as are shown, for example, in FIGS.1-3. The examples being presented are illustrative of systems andmethods that may be chosen not merely for good technical performance butalso for reasons relating to economic factors, such as, for example,initial capital cost and operating cost, as well as convenience factors,such as, for example, space requirements and portability. While threestages are shown and described herein, one skilled in the art willappreciate that any number of stages may be utilized depending on theparticular application without departing from the spirit and scope ofthe present invention.

Each of the FIGS. 1-4, merely by way of further example and withoutlimitation, are described in this specification and include legends,including numerical values (all of which are merely representativeapproximations and are not necessarily exact technical values and/orcalculations). Further, these legends are not necessarily the onlysuitable values that represent the nature and characteristics ofmaterials as applied to, affected by, and resulting from the operationsof the exemplary system(s). Not all such legends will be repeated inthis text, although all form a part of this disclosure and are believedunderstandable to persons of ordinary skill in water treatment andthermal processes. As appreciated by one skilled in the art, such dataare sometimes referred to as heat and material balances. It isspecifically to be understood and will be appreciated by one skilled inthe art that the various values indicated in the legends may have atolerance of ±20%, as they are representative approximations and notexact technical values.

Referring to FIG. 1, which is Stage #1, the waste water progresses fromthe input 10 to the output 30 successively through a pump 11, apreheater 12, a condenser 13, an additional heater 14, and a flashevaporator 15. An alternative is to have, in place of a single preheater12, a series of preheaters or heat exchangers. The heating medium orsource for the preheater(s) 12 can be excess steam available from acrystallizer 90 (see FIG. 4) and/or hot water available from thecondenser 13.

The pump 11 pressurizes the waste water 10 and elevates the pressurefrom approximately 14.7 psia (1 atm) to approximately 150 psia. Thelevel of pressurization of waste water in all stages is such that thereis no boiling of the waste water inside and across the heat exchangersurfaces of all heat exchangers used in this system. This is done toprevent formation of deposits (scales, fouling etc.) on the heatexchanger surfaces. The temperature of the waste water 10 is raised bythe preheater 12 and the condenser 13 so the input waste water to theadditional heater 14 at an inlet 17 is at approximately 150 psia and230° F. In the embodiment show in FIG. 1, the preheater 12 heats thewaste water from approximately 60° F. at the inlet 10 to approximately85° F. at an inlet 18 to the condenser 13. The preheater 12 also outputsclean, distilled water at output 20 that is generally free fromcontaminants/impurities. The condenser 13 further heats the waste waterto approximately 230° F. The heater 14 further heats the waste water toa temperature of approximately 358° F. at an inlet 19 to a flashevaporator 15.

In the exemplary system, the initial elevation in temperature is due tothe effect of saturated steam from a steam output 80 of the crystallizersubsystem 90 of FIG. 4, plus steam 15 a from the flash evaporator 15that joins with steam output 80 from the crystallizer 90 at a junction16. The steam continues to the condenser 13 and the preheater 12, untilit exits the preheater 12 as distilled water at outlet 20. Under certainoperating conditions, the steam addition from the crystallizer 90 may benegative, i.e., steam is sent as excess to the crystallizer 90 for otheruses (see FIGS. 2-3—the negative lbs/hr means that steam is actuallyflowing in the opposite direction to the crystallizer 90 and used forother purposes, e.g., as a heat source for the stripper 96).

The heating in the additional heater 14 is by a separate heating medium,such as, for example, that commercially available as DowTherm™. The useof the additional heater 14 and its heating fluid can, at least in someinstances, be favorable for overall system cost-effectiveness.

The Stage #1 output 30 has the volume of waste water reduced from theinput 10 with the salts more concentrated to approximately 23% TDS,which is increased from the initial approximately 20% TDS in theexemplary waste water at the input 10.

Stage #2 of the system as shown in FIG. 2 has elements substantiallylike those of Stage #1 as shown and described with respect to FIG. 1,but with some different operating parameters as shown in the legends inFIG. 2. Referring to FIG. 2, which is Stage #2, the brine water 30 fromStage #1 progresses to the output 50 successively through a pump 31, apreheater 32, a condenser 33, an additional heater 34, and a flashevaporator 35. An alternative is to have, in place of a single preheater32, a series of preheaters or heat exchangers. The heating medium orsource for the preheater(s) 32 can be excess steam available from acrystallizer 90 (see FIG. 4) and/or hot water available from thecondenser 33.

The pump 31 pressurizes the brine water 30 and elevates the pressurefrom approximately 14.7 psia (1 atm) to approximately 150 psia. Thetemperature of the brine water 30 is also raised by the preheater 32 andthe condenser 33 so the input brine water to the additional heater 34 atan inlet 37 is at approximately 150 psia and 230° F. In the embodimentshow in FIG. 2, the preheater 32 heats the brine water fromapproximately 60° F. at the inlet 30 to approximately 115° F. at aninlet 38 to the condenser 33. The preheater 32 also outputs clean,distilled water at output 40 that is generally free fromcontaminants/impurities. The condenser 33 further heats the brine waterto approximately 230° F. The heater 34 further heats the brine water toa temperature of approximately 358° F. at an inlet 39 to a flashevaporator 35.

In the exemplary system, the initial elevation in temperature is due tothe effect of saturated steam from a steam output 80 of the crystallizersubsystem 90 of FIG. 4, plus steam 35 a from the flash evaporator 35that joins with steam output 80 from the crystallizer 90 at a junction36. The steam continues to the condenser 33 and the preheater 32, untilit exits the preheater 32 as distilled water at outlet 40. Under certainoperating conditions, the steam addition from the crystallizer 90 may benegative, i.e., steam is sent as excess to the crystallizer 90 for otheruses (see FIGS. 2-3—the negative lbs/hr means that steam is actuallyflowing in the opposite direction to the crystallizer 90 and used forother purposes, e.g., as a heat source for the stripper 96).

The heating in the additional heater 34 is by a separate heating medium,such as, for example, that commercially available as DowTherm™. The useof the additional heater 34 and its heating fluid can, at least in someinstances, be favorable for overall system cost-effectiveness.

The Stage #2 output 50 has the volume of brine water reduced from itsinput 30 with the salts more concentrated to approximately 26% TDS,which is increased from the initial approximately 23% TDS in theexemplary brine water at its input 30.

Similarly, Stage #3 of FIG. 3 has elements substantially like those ofStage #2 as shown and described with respect to FIG. 2, but with stillsome differences in operating parameters as shown in the legends in FIG.3. Referring to FIG. 3, which is Stage #3, the brine water 50 from Stage#2 progresses to the output 70 successively through a pump 51, apreheater 52, a condenser 53, an additional heater 54, and a flashevaporator 55. An alternative is to have, in place of a single preheater52, a series of preheaters or heat exchangers. The heating medium orsource for the preheater(s) 52 can be excess steam available from acrystallizer 90 (see FIG. 4) and/or hot water available from thecondenser 53.

The pump 51 pressurizes the brine water 50 and elevates the pressurefrom approximately 14.7 psia (1 atm) to approximately 150 psia. Thetemperature of the brine water 50 is also raised by the preheater 52 andthe condenser 53 so the input brine water to the additional heater 54 atan inlet 57 is at approximately 150 psia and 230° F. In the embodimentshow in FIG. 3, the preheater 52 heats the brine water fromapproximately 60° F. at its inlet 50 to approximately 117° F. at aninlet 58 to the condenser 53. The preheater 52 also outputs clean,distilled water at output 60 that is generally free fromcontaminants/impurities. The condenser 53 further heats the brine waterto approximately 230° F. The heater 54 further heats the brine water toa temperature of approximately 358° F. at an inlet 59 to a flashevaporator 55.

In the exemplary system, the initial elevation in temperature is due tothe effect of saturated steam from a steam output 80 of the crystallizersubsystem 90 of FIG. 4, plus steam 55 a from the flash evaporator 55that joins with steam output 80 from the crystallizer 90 at a junction56. The steam continues to the condenser 53 and the preheater 52, untilit exits the preheater 52 as distilled water at outlet 60. Under certainoperating conditions, the steam addition from the crystallizer 90 may benegative, i.e., steam is sent as excess to the crystallizer 90 for otheruses (see FIGS. 2-3—the negative lbs/hr means that steam is actuallyflowing in the opposite direction to the crystallizer 90 and used forother purposes, e.g., as a heat source for the stripper 96).

The heating in the additional heater 54 is by a separate heating medium,such as, for example, that commercially available as DowTherm™. The useof the additional heater 34 and its heating fluid can, at least in someinstances, be favorable for overall system cost-effectiveness.

The Stage #3 output 70 has the volume of brine water reduced from itsinput 50 with the salts more concentrated to approximately 31% TDS,which is increased from the initial approximately 26% TDS in theexemplary brine water at its input 50. In addition, the volume of waterwith the salts is reduced at the outlet 70 of Stage #3 by 55% from thatat the inlet 10 of Stage #1.

The exemplary system includes multiple (three) concentration stages(FIGS. 1-3) that are substantially alike in the combination of equipmentused. However, other exemplary systems with multiple concentrationstages may have individual stages of more varied combinations ofequipment without departing from the spirit and scope of the presentinvention.

The inputs and outputs of the individual stages can all be simply at14.7 psia or at a pressure chosen by the process operator to optimizeenergy utilization within the process. Advantage can be taken withineach stage to pressurize the inputs to the respective flash evaporators15, 35, 55 to about 150 psia. The level of pressurization of waste waterin all Stages is such that there is no boiling (nucleate or other type)of the waste water inside and across the heat exchanger surfaces of boththe condensers and preheaters of each Stage. This prevents the formationof deposits (scales, fouling etc.) on the heat exchanger surfaces andreduces the requirement for cleaning of the heat exchangers. Thisresults in the reduction of the operating cost. In this example, such anincrease in pressure can result in a temperature of about 358° F. inputto the flash evaporators 15, 35, 55 for quicker, more efficientseparation and concentration in the respective flash evaporator 15, 35,55.

FIG. 4 represents an exemplary embodiment of applying the output brinewater (line 70) of the Stage #3 treatment (FIG. 3) to a plasmacrystallizer 90. The plasma crystallizer 90 is an example of a knownthermal reactor that can be used to finish separation of water fromsalts dissolved therein. One skilled in the relevant art willappreciate, however, that other thermal reactors may also be usedwithout departing from the spirit and scope of the present invention.The example of a plasma reactor, which can be consistent with knownplasma gasification/vitrification reactors, operated with one or moreplasma torches 92, as is well-known in published literature, is believedto provide opportunity for a favorable cost-benefit ratio.

In general, for multistage operation, the plasma crystallizer 90 (orother reactor) is typically utilized after the final concentration stagewhen the output brine water has been concentrated to a desired level, asdescribed in the above example. It can also be suitable to have amultistage system not only for salts concentration (as in FIGS. 1-3),but also a separation subsystem with a reactor (e.g., plasmacrystallizer 90) after any individual one of the early concentrationstages (e.g., after either, or both, of Stages #1 and #2). However, itis generally more cost effective to have a single separation subsystemafter the last of a determined number of concentration stages for thedesired separation.

In general, any thermal reactor may be used to separate the salts andthe water. A reactor operated to produce disposable salts (referred toherein as a “crystallizer”) is generally suitable. Where the salts havetoxicity, it may be desirable to operate the reactor in a manner so theyare vitrified or made into glass. Accordingly, any reference to acrystallizer herein can also include a vitrifier.

As shown in FIG. 4, the crystallizer has a salts output at an outlet 85that is generally equivalent to the total salts content of the originalwaste water. The water output of the total system is recovered as clean,distilled water from the preheaters 12, 32, 52 of the respective Stagesof FIGS. 1-3, and/or may be recovered directly from steam exiting thecrystallizer 90.

FIG. 4 shows the brine water 70 entering the crystallizer 90 withoutneed for additional pressurization. FIG. 4 also shows how steam from thecrystallizer 90 can be redirected back to the respective earlier Stagesof FIGS. 1-3. The steam output from the crystallizer 90 at line 80 maybe provided back to the various Stages #1, #2 and #3 and used forheating by the respective preheaters and condensers therein. Also, FIG.4 shows an “Excess Steam to Stripper” of a certain amount at line 94.This steam 94 is used in a stripper 96 which is utilized to remove, forexample, Volatile Organic Compounds (“VOCs”) from the waste water beforeprocessing. Some excess steam from the crystallizer 90 may also be usedfor other purposes, e.g., to preheat the input waste water in apreheater or condenser.

Before treatment in the Stages shown in FIGS. 1-3, the incoming wastewater 9 can be first, in this exemplary embodiment, sent to the stripper96 where the steam 94 is used to remove VOCs from the waste water 9.Alternatively, the excess steam 94 may be used to preheat air in aseparate heater first (not shown), and then the heated air can be usedin the stripper 96. The stripped waste water 10 is sent as feed at theinput 10 of Stage #1 (see FIG. 1). The VOCs which are removed from thewaste water 9 exit the stripper 96 through a conduit 98 which connectsto the plasma crystallizer 90. Additionally or alternatively, acondenser with a knock-out pot (not shown) can be used between theplasma crystallizer 90 and the stripper 96 with the condensed VOCs (aswell as any stripped VOCs) fed directly to the plasma crystallizer 90.The VOCs are fed in front of the plasma torch 92 (e.g., along with brinewater from Stage #3) such that they intensely mix with the hightemperature gases exiting from the plasma torch 92. The plasma torch 92is operated using appropriate gas (e.g., air, oxygen, hydrogen, etc.)that will aid in, or result in, the complete destruction of the VOCs.The VOCs are substantially converted to carbon dioxide and steam. Theheat generated by this conversion of VOCs to carbon dioxide and steam isutilized in the plasma crystallizer 90, along with heat inputted throughthe plasma torch 92, to vaporize the water from the brine water 70. Thisreduces the amount of heat and the corresponding amount of electricityutilized in the plasma torch 92 of the plasma crystallizer 90, thusincreasing its cost effectiveness.

The steam exiting the plasma crystallizer 90 can be, in this exemplaryembodiment, periodically vented to the atmosphere (not shown) to helpkeep the levels of non-condensable gases low enough such that they donot degrade the performance of the heat exchangers used in the inventivesystem and process.

It is therefore seen that systems and processes in accordance with thepresent invention can make use of known and available components (suchas, for example, flash evaporators for concentration of salts and plasma(or other) gasifier reactors for crystallization (or vitrification) ofthe salts) in particular innovative ways with insight as to both thecapital cost and the operating cost. A need for such cost effectivewater treatment has been heightened by practices, such as, for example,the use of large amounts of water in natural gas drilling. However, thepresent invention may be used in any situation where impurities to beremoved exist.

In general summary, but without limitation, the present invention can becharacterized in the following ways, for example: A system, and acorresponding method, in which waste water is supplied to one or morestages of equipment including a pump for pressurizing the water (e.g.,to about 150 psia), a preheater that heats the pressurized waste water(as well as removing distilled water) well above normal boilingtemperature, and a condenser that effects further heating of thepressurized waste water. The system additionally has a heater after thecondenser of each stage that raises the temperature even higher wellabove normal boiling temperature. That heater is operated with a heatingfluid other than steam from within the system. Then, the heated andpressurized waste water goes to a flash evaporator, or other device,that receives the heated, pressurized waste water and results in fluidevaporation and concentration of solids that were in the waste water.In, for example, instances in which the waste (brine) water withconcentrated solids cannot be otherwise readily and safely disposed of,a thermal or pyrolytic reactor is provided to crystallize or otherwiseyield a form of the solids that can be readily and safely disposed of.In one form, such a reactor may also be applied as a heater for theoriginal incoming waste water. Also, or alternatively, such a reactormay be used to form a vitrified glass of the salts output of any watertreatment system that produces a brine water.

It will be apparent to those skilled in the art that numerousmodifications and variations of the described examples and embodimentsare possible in light of the above teachings of the disclosure. Thedisclosed examples and embodiments are presented for purposes ofillustration only. Other alternate embodiments may include some or allof the features disclosed herein. Therefore, it is the intent to coverall such modifications and alternate embodiments as may come within thetrue scope of this invention, which is to be given the full breadththereof. Additionally, the disclosure of a range of values is adisclosure of every numerical value within that range.

I claim:
 1. A method of treating waste water comprising the steps of:(a) receiving waste water at a first pressure between 11.8-17.6 psia anda first temperature between 48-72° F., the waste water comprisingdissolved solids and volatile organic compounds; (b) pressurizing thereceived waste water to a second pressure between 120-180 psia; (c)preheating the pressurized waste water to a second temperature between68-140° F., wherein said preheating step produces a distilled water anda pressurized/preheated waste water without boiling of the waste wateracross heat transfer surfaces; (d) heating the pressurized/preheatedwaste water to a third temperature between 286-430° F. to produce apressurized/heated waste water without boiling of the waste water acrossheat transfer surfaces; (e) evaporating the pressurized/heated wastewater in an evaporator to remove dissolved solids by evaporation causedby depressurization of the waste water to produce a first steam and abrine water, wherein the brine water has a total dissolved solidscontent greater than a total dissolved solids content of the receivedwaste water; and (f) crystallizing the brine water to produce a solidmass of waste product and a second steam, wherein the second steamproduced by step (f) is used as a heat source in at least one of steps(c) and (d), and wherein step (f) uses a plasma torch to crystallize thebrine water.
 2. The method of claim 1, wherein step (d) comprises thesteps of: (d1) further heating the pressurized/preheated waste water toa fourth temperature between 184-276° F. to produce apressurized/further heated waste water without boiling of the wastewater across heat transfer surfaces; and (d2) still further heating thepressurized/further heated waste water to the third temperature toproduce the pressurized/heated waste water without boiling of the wastewater across heat transfer surfaces.
 3. The method of claim 2, whereinthe first steam produced in step (e) is used as a heat source in atleast one of steps (c) and (d1).
 4. The method of claim 3, wherein anexternal heat source is used for heating in step (d2).
 5. The method ofclaim 1, wherein the first steam produced in step (e) is used as a heatsource in at least one of steps (c) and (d).
 6. The method of claim 1,wherein an external heat source is used for heating in step (d).
 7. Themethod of claim 1, wherein steps (a)-(e) comprise a stage, and whereinthe method is performed in multiple stages operated in series with thebrine water output by step (e) in one stage used as the received wastewater in step (a) of a next stage, and wherein the brine water output bystep (e) in a last stage is input to the crystallizer at step (f). 8.The method of claim 7, wherein the brine water output in step (e) ofeach stage has a total dissolved solids content that is higher than thatof a previous stage.
 9. The method of claim 1, wherein steps (a)-(e)comprise a stage, and wherein the method is performed in multiple stagesoperated in series with the brine water output by step (e) in one stageused as the received waste water in step (a) of a next stage, andwherein the brine water output by step (e) in a last stage is input tothe crystallizer at step (f).
 10. The method of claim 9, wherein thebrine water output in step (e) of each stage has a total dissolvedsolids content that is higher than that of a previous stage.
 11. Themethod of claim 1, wherein the second steam produced by step (f) is usedas a heat source in at least one of steps (c) and (d).
 12. The method ofclaim 1, further comprising the steps of: (b′) prior to step (b),removing the volatile organic compounds from the received waste water,wherein the removed volatile organic compounds are used as a fuel by theplasma torch to crystallize the brine water.
 13. The method of claim 12,wherein the second steam produced by step (f) is used as a heat sourcein step (b′).
 14. The method of claim 1, wherein step (f) produces avitrified glass of the salts in the brine water as the solid mass ofwaste product.
 15. A system for treating waste water comprising: a pumpreceiving waste water at a first pressure between 11.8-17.6 psia and afirst temperature between 48-72° F. and pressurizing the received wastewater to a second pressure between 120-180 psia, the waste watercomprising dissolved solids and volatile organic compounds; a preheateroperatively connected to the pump and receiving the pressurized wastewater from the pump and preheating the pressurized waste water to asecond temperature between 68-140° F. to produce a distilled water and apressurized/preheated waste water without boiling of the waste wateracross heat transfer surfaces; a condenser operatively connected to thepreheater and receiving the pressurized/preheated waste water from thepreheater and heating the pressurized/preheated waste water to a fourthtemperature between 184-276° F. to produce a pressurized/heated wastewater without boiling of the waste water across heat transfer surfaces;a heater operatively connected to the condenser and receiving thepressurized/heated waste water from the condenser and further heatingthe pressurized/heated waste water to a third temperature between286-430° F. to produce a pressurized/further heated waste water withoutboiling of the waste water across heat transfer surfaces; an evaporatoroperatively connected to the heater and receiving the pressurized/heatedwaste water from the heater and removing the dissolved solids from thepressurized/heated waste water by evaporation caused by depressurizationof the waste water to produce a first steam and a brine water, whereinthe brine water has a total dissolved solids content greater than atotal dissolved solids content of the received waste water; and acrystallizer operatively connected to the evaporator crystallizing thebrine water to produce a solid mass of waste product and a second steam,wherein the second steam produced by the crystallizer is used as a heatsource by at least one of the preheater and condenser, and wherein thecrystallizer comprises a plasma crystallizer and includes a plasma torchfor vaporizing the water from the brine water and producing the solidmass of waste product and the second steam.
 16. The system of claim 15,wherein the first steam produced by the evaporator is used as a heatsource by at least one of the preheater and the condenser.
 17. Thesystem of claim 15, wherein the pump, preheater, condenser, heater andevaporator comprise a stage, and wherein the system comprises multiplestages operated in series with the brine water output by one stage usedas the received waste water of a next stage, and wherein the brine wateroutput by a last stage is input to the crystallizer.
 18. The system ofclaim 17, wherein the brine water output by each stage has a totaldissolved solids content that is higher than that of a previous stage.19. The system of claim 15, further comprising a stripper initiallyreceiving the waste water and removing the volatile organic compoundsfrom the waste water prior to the waste water being pressurized by thepump, wherein the removed volatile organic compounds are used as a fuelby the plasma torch to crystallize the brine water.
 20. The system ofclaim 19, where the second steam produced by the crystallizer is used asa heat source by the stripper.
 21. The system of claim 15, wherein thesolid mass of waste product comprises a vitrified glass of the salts inthe brine water.
 22. The system of claim 15, wherein the heater uses anexternal heat source.